At nearly 41 years old, the CN Tower is making a very sensible, middle-aged adjustment: it's getting transition lenses.

The iconic structure in the heart of Toronto has revealed a major renovation on its viewing deck, where two self-tinting, floor-to-ceiling window walls were just unveiled. The windows are the first part of a larger $16-million renovation project at the CN Tower, which is celebrating its 41st anniversary this year.

The new windows were kept under wraps until completion this week, with crews working behind tarps to install more than 6,000 kilograms of glass without being noticed. The new windows are designed to automatically adjust their opacity based on temperature and available sunlight, so the viewing deck remains comfortable for tourists.

CN Tower COO Neil Jones touted the new windows as the beginning of a major revamp for the tower's lookout level.

"It's really a panoramic view," he told CTV Toronto at the unveiling Monday. "You can get so close to the edge… and look straight down…. 1,150 feet up."

The new design also removed a low barrier that used to be in place near the old windows, which would prevent some individuals from getting close enough to take in a full view.

"I actually had to stand up on my wheelchair to look out the window," one boy said. "But this, it provides a view for everyone."

Another boy in a wheelchair also hailed the change. "The view is beautiful," he said. "We can see from one city to the next."

Jones says the CN Tower renovations will add more glass floors and open space to the viewing area, so visitors can get an even better view of Toronto from its highest point.

With files from CTV Toronto